[Python-Dev] Re: Possible solution for PEP250 and bdist_wininst

[M.-A. Lemburg]

Thomas Heller wrote:
> 
> I have a possible solution for this problem.
> 
> (I'll use the name INSTALLPATH for installation directory stored
> in the registry under the key
> HKEY_LOCAL_MACHINE\Software\Python\PythonCore\<version>\InstallPath).
> 
> The bdist_wininst installer at _install_ time sets the PYTHONHOME
> environment variable to INSTALLPATH, then loads the python dll
> and retrieves the 'extinstallpath' attribute from the sys module:
> 
>     wwsprintf(buffer, "PYTHONHOME=%s", INSTALLPATH);
>     _putenv(buffer);
>     Py_SetProgramName(modulename);
>     Py_Initialize();
>     pextinstallpath = PySys_GetObject("extinstallpath");
>     Py_Finalize();
> 
> If this is successful, the (string contents of) pextinstallpath
> is appended to INSTALLPATH, and that will be the directory where
> the package will be installed. If unsuccessful, INSTALLPATH will
> be used as before.

Sounds OK.
 
> I'm unsure about the change to site.py, but this should work:
> 
> diff -c -r1.26 site.py
> *** site.py     2001/03/23 17:53:49     1.26
> --- site.py     2001/07/13 15:32:27
> ***************
> *** 140,153 ****
>                                    "python" + sys.version[:3],
>                                    "site-packages"),
>                           makepath(prefix, "lib", "site-python")]
> -         elif os.sep == ':':
> -             sitedirs = [makepath(prefix, "lib", "site-packages")]
>           else:
> !             sitedirs = [prefix]
>           for sitedir in sitedirs:
>               if os.path.isdir(sitedir):
>                   addsitedir(sitedir)
> 
>   # Define new built-ins 'quit' and 'exit'.
>   # These are simply strings that display a hint on how to exit.
>   if os.sep == ':':
> --- 140,154 ----
>                                    "python" + sys.version[:3],
>                                    "site-packages"),
>                           makepath(prefix, "lib", "site-python")]
>           else:
> !             sitedirs = [prefix, os.path.join(prefix, "lib", "site-packages")]
>           for sitedir in sitedirs:
>               if os.path.isdir(sitedir):
>                   addsitedir(sitedir)
> 
> + if os.sep == '\\':
> +     sys.extinstallpath = os.path.join(sys.prefix, "lib", "site-packages")
> +

Why not do this for all platforms (which support site-packages) ?

-- 
Marc-Andre Lemburg
CEO eGenix.com Software GmbH
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